Binding of anti-band 3 autoantibody to oxidatively damaged erythrocytes. Formation of senescent antigen on erythrocyte surface by an oxidative mechanism.
Incubation of human erythrocytes oxidized by iron catalysts, ADP/Fe3+ or xanthine/xanthine oxidase/Fe3+, with autologous IgG resulted in IgG binding as detected by enzyme immunoassay using protein A-beta-galactosidase conjugate. The binding of autologous IgG to ADP/Fe3(+)-treated erythrocytes maximized when the cells were treated with 1.8:0.1 mM ADP/Fe3+, and declined when treated above this concentration, suggesting that autologous IgG binds to moderately but not to excessively oxidized erythrocytes. The antibody involved in the binding was anti-Band 3, the autoantibody known to bind to aged erythrocytes, because isolated anti-Band 3 bound to the oxidized cells, but anti-Band 3-depleted autologous IgG did not. In addition, purified Band 3 inhibited the autologous IgG binding. Anti-alpha-galactosyl IgG, another natural antibody which has been reported to bind to aged erythrocytes, did not bind to the oxidized cells. Oxidation of membrane lipids, SH-groups of membrane proteins, and Hb of these cells was slight, but the cells contained an increased amount of membrane-bound native Hb, indicating that the oxidized cell membrane has an altered property. alpha-Tocopherol prevented the lipid oxidation and the subsequent IgG binding. Reduction of the oxidized erythrocytes with dithiothreitol resulted in a loss of the IgG binding. These results suggest that anti-Band 3 binding sites (Band 3 senescent antigen) are formed on moderately oxidized erythrocytes as a result of oxidation of membrane protein SH-groups which can be mediated by the membrane lipid oxidation and that formation of the anti-Band 3 binding sites on the oxidized cells is an essentially reversible membrane event which is linked to oxidation and restoration of the protein SH-groups.
Beppu
M
M
Tokyo College of Pharmacy, Japan.
Mizukami
A
A
Nagoya
M
M
Kikugawa
K
K
D000244:Adenosine Diphosphate / Q000494:pharmacology; D001457:Anion Exchange Protein 1, Erythrocyte / Q000276:immunology*; D000936:Antigen-Antibody Complex; D001323:Autoantibodies / Q000302:isolation & purification; D002846:Chromatography, Affinity; D004905:Erythrocyte Aging; D004910:Erythrocyte Membrane / Q000502:physiology*; D006801:Humans; D007074:Immunoglobulin G / Q000302:isolation & purification / Q000378:metabolism*; D007501:Iron / Q000494:pharmacology; D007700:Kinetics; D008954:Models, Biological; D010084:Oxidation-Reduction; D019820:Xanthine; D014969:Xanthine Oxidase / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D001457:Anion Exchange Protein 1, Erythrocyte; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D007074:Immunoglobulin G; D014970:Xanthines; D019820:Xanthine; D000244:Adenosine Diphosphate; D007501:Iron; D014969:Xanthine Oxidase